Abstract: The flood control decision is a very complicated decisive thought activity. It is not noly supported by a vast amount of data-information, but also by a large number of text-information. On the base of analysing the requirement for the text-information in the process of making flood control decision, we widely collect variable relative text-information, make the classification of the information, and determine the stucture system of the information for flood control knowledge base. After that, with the help of on line Windows Help function, we develop Yangtze River Flood Control Knowledge Base Subsystem. The subsystem possesses the features of user-interface friend and easy operating. It can supply convenient and quick text-information support for flood control decision-makers.